There are known devices having a suction attachment connected to a vacuum pump and which is applied to workpiece in order to be used as load hook. Further known are suction attachments in connection with drilling devices, whereby these suction attachments serve as equipment holders (DE 35 01 753, DOS 27 44 463). From French Patent 1 595 727 a suction cup with a compressible pad made of porous rubber is known.
Finally, vacuum holding devices are known which work with plate-shaped or cup-shaped suction elements, which on the side facing away from the workpiece to be held are provided with sealing lips or a sealing ring, whereby the latter is made of a very soft, elastically deformable material and is designed as special, separate part and connected with the suction element (DE-AS 27 23 16).
The task of these known devices is to hold or to transport loads, such as drilling equipment. A precondition for the acceptable operation of these devices is a basically even, smooth, dense and homogeneous surface of the load to be transported. The suction elements known from DE-AS 27 23 616 and French Patent 1 595 727 can also be used on a substrate which is not completely even, but provided a predetermined negative pressure is constantly maintained.